A six-year court battle waged by the feds against an ExxonMobil policy mandating the retirement of all corporate pilots at the age of 60 was dealt its second defeat in a Dallas federal court. The challenge, filed by the Equal Employment Opportunity Commission, characterized the policy as ageist and in violation of federal law.

The district court, as before, sided with ExxonMobil. The multinational oil and gas company argued that its policy mirrored a previous Federal Aviation Administration rule setting the same limit. In 2008, Judge Ed Kinkeade, the magistrate who authored the opinion, agreed and tossed EEOC's challenge. The commission appealed and won a reversal in the 5th U.S. Circuit Court of Appeals, which remanded the case to district court.

Kinkeade remained equally unconvinced in the latest go-round, denying motions to strike ExxonMobil's witnesses, who included neurologists and the director of Dallas' Baylor Heart and Vascular Institute. Each testified to the unpredictability of incapacitating heart attacks and strokes. Indeed, he ruled, under federal law, an employer can't discriminate based on age. Unless, and that's a big unless, youth is a "qualification reasonably necessary to the normal operation of a particular business."

In this case, that business is flying Exxon honchos all over the world in private jets that start at around $65 million apiece.

"Generally, Exxon contends that aging causes a progressive physiological and cognitive decline, and that it remains impossible to determine whether or when an individual pilot will experience a medical event jeopardizing aviation safety," the judge writes. "This was and is the rationale in support of the FAA's age-based rule."